1. Field of the Invention
This invention relates to computer keyboards and particularly to the sounds emitted from a keyboard as keys of the keyboard are stroked.
2. Description of Background
Technology now exists that makes it possible to determine which keys are stroked on a computer keyboard by recording the sound that emanates from the keyboard as the keys are stroked and processing the recorded sound in a personal computer (PC).
Using input from an unsophisticated PC microphone and processing the input using standard machine learning and speech recognition techniques it is possible to recreate typed input with up to 96% accuracy. Using a two-phase process of training followed by recognition, researchers were able to successfully recreate both English and random (password) input from multiple keyboards, across various (quiet and noisy) environments. While techniques such as the one described are still relatively new, one can envision several nefarious uses for the technology. For example, a person using a parabolic microphone could sit in a public setting, such as a coffee shop with Internet access, and eavesdrop on other patrons; recording sensitive information keyed into their computers, such as passwords and credit card numbers.
Accordingly, there is a need in the art for methods and apparatuses that inhibit the detection of keystrokes by the sounds emanating during stroking of the keys.